The invention concerns a device for attaching tubular segments of plastic and other film materials on vessels such as bottles or cans.
Such a device is already known, where vacuum suckers are arranged separately and rigidly about a separate rotor rotating about a vertical axis and carrying pairs of expanding mandrels. The rotor turns next to a feeding device for the flat individual tubular film segments. The revolving vacuum grippers or suckers cooperate with a fixed sucker arranged in the transfer region which sucker partially opens the tubular segments. Into the partly opened tubular segments are pushed the expanding mandrels that are mounted for radial movement on the rotor and are widened at the same time, opening the tubular segments by the rotary movement of the rotor alone. This device has fairly high output because of the substantially continuous operation. A problem, however, is the transfer of the tubular segments between the suckers and the expanding mandrels, whose separate paths of revolution overlap only briefly, so the entire film segment unfolding or opening process must take place during the transfer. This can only be ensured with relatively stable and small-faced tubular segments, as they are used, for example, for covering bottles. Even so there is a risk of an undesired slipping or tearing of the tubular segments. This known device is not suitable for applying labels and large-surfaced tubular film segments or sleeves, as they are used, for example, as label substitutes for enveloping the bodies of bottles.
In another known device for applying tubular segments on bottles a first rotor is behind the segment feeding device and revolves with the individual suckers about a horizontal axis of rotation. A second rotor for attaching the individual tubular segments directly on the vessels has suckers instead of expanding mandrels arranged in pairs at regular intervals. In this known device a greater range of rotor revolution is available for opening the tubular segments, but again only small-faced tubular segments or tubular segments with a smaller diameter can be processed, since it is hardly possible to keep large diameter tubular segments open with a single pair of suckers, and thus to place them on the vessels.
Finally a device is known for applying tubular segments on momentarily stopped vessels with a single rotor revolving intermittently about a horizontal axis of rotation, which rotor is provided with several radially directed pairs of split mandrels at regular intervals. The rotor is preceded by a first pair of suckers grasping the tubular segments from a feeding device and turning them over the split mandrels after which a second pair of suckers pull the tubular segments from the mandrels and place them on the vessels, whereby the two pairs of suckers rest on a common ascending and descending carriage. This known device is not suitable for high outputs because of its strictly intermittent operation.